The problems of waste management have been well documented. Our society is experiencing a crisis due to the closing of our landfills, as they are filled to capacity. For various reasons, the opening of new landfill sites is not a viable alternative. The unpleasant odors, the vermin and the rodents associated with landfills make the placement of such sites unwelcome and unwanted in communities throughout the land. Yet the need for a solution increases as the garbage piles up.
In the ordinary landfill, refuse is dumped into a hole or some other excavated site and then covered with topsoil or other earth covering. This process is repeated continuously, one layer upon another, raising the level of the land. While methods have been developed which permit the aeration of the buried refuse, these methods do not substantially accelerate the decomposition process. For instance, in U.S. Pat. No. 4,483,641, a waste disposal landfill is disclosed having a series of air intake pipes and exhaust pipes extending from the atmosphere through the covering layer and into the garbage heap. However, such ventilation means, which are intended to evaporate accumulated water, are not appropriate for the purposes of expediently reducing the volume of garbage through an accelerated decomposition process. This is because air flow is localized within particular regions of the landfill.
The disadvantage of capping a landfill is that it prevents water (as well as air) from commingling with the refuse. As a result, the natural decomposition processes are inhibited. A typical capped landfill is no more than a stagnant, nonbiodegrading pile of refuse. This is despite the fact that they are largely composed of paper products and other biodegradables. A recent observation of garbage in a landfill which had been agitated revealed newspapers dating back to 1980 which were readable and fully in tact.
It has been found that aerobic treatment of landfill material, where air and water are mixed with solid waste, results in a 7 to 10 times faster decomposition than an anaerobic treatment that lacks water and air. Furthermore, if the pH of the environment is below 4 then decomposition ceases to occur, which will inevitably result as without water and air, hydrogen sulfide (H.sub.2 S) is generated. Aerobic processes are less sensitive to changes in pH.